src: remove declarations of removed BaseObject static fns

These were removed in 5c86f22, so their declarations should be
removed from class declarations too.

PR-URL: #59093
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Daeyeon Jeong <daeyeon.dev@gmail.com>

Author: addaleax

src/base_object.h

@@ -128,11 +128,6 @@ class BaseObject : public MemoryRetainer {
   // a BaseObjectPtr to this object.
   inline void Detach();
 
-  static inline v8::Local<v8::FunctionTemplate> GetConstructorTemplate(
-      Environment* env);
-  static v8::Local<v8::FunctionTemplate> GetConstructorTemplate(
-      IsolateData* isolate_data);
-
   // Interface for transferring BaseObject instances using the .postMessage()
   // method of MessagePorts (and, by extension, Workers).
   // GetTransferMode() returns a transfer mode that indicates how to deal with